Performance obligations satisfied over time refer to situations where an entity's promise to provide goods or services to a customer is fulfilled progressively, rather than all at once. According to IFRS 15, an entity satisfies a performance obligation and recognizes revenue over time if any one of the following criteria is met:

1. Customer Consumes Benefit As Entity Performs: The customer simultaneously receives and consumes the benefits provided by the entity as the entity performs. For example, a cleaning service would recognize revenue over time as it provides the service because the customer is benefitting from the service as it is performed.
2. Creation or Enhancement of a Customer-Controlled Asset: The entity’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced. For instance, a builder constructing a building on a customer's land would recognize revenue over time because the customer controls the asset (the building) as it's being created.
3. No Alternative Use and Right to Payment: The entity’s performance does not create an asset with an alternative use to the entity, and the entity has an enforceable right to payment for performance completed to date. This might apply in a situation where an entity is creating a highly customized piece of machinery that couldn't be sold to another customer, and where the contract provides the entity with the right to payment for work completed to date.

In situations where a performance obligation is satisfied over time, the entity needs to determine a method for measuring progress towards complete satisfaction of that obligation. The objective is to depict an entity's performance in transferring control of goods or services promised to the customer. That method of measuring progress could be output methods (such as units produced or delivered) or input methods (such as labor hours expended, costs incurred, or passage of time).